There is a need for a pipe fitting which can be readily adjusted in length. Such a length-adjustable pipe fitting would be useful, for example, in adjusting the height of irrigation sprinkler heads above a buried main supply line.
In the present state of the irrigation construction arts, swing joints are commonly used to provide a flexible means of connecting pipe fittings bearing irrigation sprinkler heads to a main supply line. The use of swing joints allows the height of the sprinkler heads to be adjusted in the field to meet particular grade elevation requirements—but only during the construction of the irrigation system.
After construction of an irrigation system, however—when top soil grading is finished and soil compacted around the pipe fittings bearing the sprinkler heads—any additional adjustments of the height of any one of the sprinkler heads necessarily requires that the entirety of the pipe fitting bearing the sprinkler head and much of the associated swing joint must be excavated. Excavating the pipe fitting and swing joint is time-consuming and expensive and frequently results in damage to the sprinkler head, the pipe fitting bearing the sprinkler head, the swing joint and/or the main supply line.
Accordingly, there is a need for a pipe fitting which can be readily adjusted in length.